Refractive state and correction of refractive errors among mentally retarded adults in a central institution.

In a population of 212 mentally retarded, retinoscopy could be performed in 342 eyes in 182 patients. Of these, 334 eyes were phakic. Hypermetropia of +5 or more was encountered in 20 eyes (6.0%), while 26 (7.8%) had a myopia of -5 or more. The most striking finding was a high number of severe astigmatism, cylindrical power of -3.25 or more being present in 29 eyes (8.7%). Glasses were initially prescribed to 88 patients. Six months after the prescription, 59.1% used their glasses regularly. Aspects of glass prescription to mentally retarded are discussed in the paper.